Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J29/00—Catalysts comprising molecular sieves
  • B01J29/89—Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium

Definitions

• EP-A-4676 describes a direct process for the production of oximes, among others cyclohexanone-oxime, wherein a mixture of ketone, ammonia and oxygen is contacted, at a temperature of from 50° to 500°C, with a solid catalyst having a certain surface area.
• Preferred catalysts are, among many others, ca­talysts comprising silica and/or zirconia and/or an oxide of a transition metal of Group 3-8 of the Periodic Table.
• DE-C-1 245 371 teaches the preparation of cyclohexanone-­oxime by catalytic reaction, in the liquid phase, of cyclo­hexanone with ammonia and hydrogen peroxide at 5 to 40°C, in the presence of a catalyst consisting of phospho-tungstic acid or of similar compounds.
• a drawback of this method is, however, that this type of catalyst is difficult to handle, particularly, during the separation of the product from the catalyst.
• the present invention relates to a catalytic process for preparing cyclohexanone-oxime by reacting cyclohexanone with NH3 and H2O2 in the liquid phase at a temperature of from 25 to 100°C and at a pressure equal to or higher than atmos­pheric pressure, which process is characterized in that the catalyst substantially consists of a highly crystalline, SiO2-containing substance having a zeolitic structure and, in particular, of a titanium-silicalite, optionally in admix­ture with an inert binder.
• Titanium-silicalites are known com­pounds which, for example, are described in GB-A-2 024 790 and 2 071 071.
• the reaction temperature preferably is in the range of from 40 to 90°C. Tests carried out at 15°C have provided results that are not completely satisfactory.
• a pressure above atmospheric pressure is preferred since it promotes the development of the reaction.
• silicalite I see, e.g., US-A-4 061 724
• silicalite II zirconium-silicalites
• hafnium-silicalites zirconium-silicalites
• metal­silicalites e.g., borosilicates (boralites), beryllo­silicates, chromo-silicates, vanadium-silicates, zirconium­silicates, gallium-silicates and ferro-silicates which are, in part, described in GB-A-2 024 790.
• a third class of catalysts of analogous type consists of the known aluminium-silicates, generally known as "zeolites", particularly the zeolites of type Y, the zeolites ZSM5, the zeolites ZSM 11 and the other zeolites ZSM described in EP-A-129 239, 141 514 and 143 642, as well as the zeolites MB 28 described in EP-A-21 445.
• zeolites particularly the zeolites of type Y, the zeolites ZSM5, the zeolites ZSM 11 and the other zeolites ZSM described in EP-A-129 239, 141 514 and 143 642, as well as the zeolites MB 28 described in EP-A-21 445.
• the titanium-silicalite mentioned above is replaced, at least in part, by a zirconium-silicalite or a boralite.
• the process according to the present invention can be carried out either continuously or discontinuously, provided that reactors with surfaces that are resistant to hydrogen peroxide are used.
• reactors with surfaces that are resistant to hydrogen peroxide are used.
• 0.1 to 50 parts by weight preferably from 1 to 20 parts by weight
• pure catalyst excluding binder
• a space velocity of from 0.1 to 100 kg/h of cyclohexanone (C6H 10 O) per kg of catalyst.
• the molar ratio of H2O2:C6H 10 O is, generally, in the range of from 0.5 to 2.5 and, preferably, from 1 to 1.5, whereby H2O2 means 100% pure hydrogen peroxide (i.e., dilution water excluded).
• Water (H2O) is the most suitable liquid vehicle for the reaction.
• it is also possible to use or­ganic water-soluble solvents capable of dissolving both pure ammonia and its aqueous solutions such as, e.g., methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tertiary butanol and mixtures thereof. Solvents with car­bonyl functions such as aldehydes and ketones should be excluded.
• reaction water which is formed according to the equation: gradually increases the amount of liquid vehicle as the con­version to oxime proceeds.
• conside­rable amounts of peroxy-di-cyclohexyl-amine of the formula are also formed.
• Ammonia should always be added before the hydrogen peroxide and in excess (NH3: C6H 10 O ⁇ 1, preferably ⁇ 1.5 moles/mol). Otherwise, undesired side-reactions occur.
• the cyclohexanone-oxime can be separated by different methods, for example, through extrac­tion with suitable solvents such as benzene, toluene and the cyclohexanone as used for the synthesis, whereby a hydropho­bic organic phase and an aqueous phase are formed.
• Cyclo­hexanone-oxime and unreacted cyclohexanone form the organic layer.
• the aqueous layer which contains the excess NH3 as well as traces of cyclohexanone and oxime can be re­cycled to the reaction zone (ammoximation zone).
• a 32% by weight aqueous solution of hydrogen per­oxide was fed to the reactor by means of a metering pump. After 15 minutes, the temperature in the reactor reached 60°C while the pressure rose to a value of from 80 to 93 KPa (600 to 700 mm Hg) above atmospheric pressure. The addition of H2O2 was performed within 3.5 hours, during which time the pressure decreased. The temperature was maintained at 60°C and stir­ring was continued for a further 1.5 hours, whereafter the test was stopped and the mixture was cooled.
• Example 1 was repeated, varying temperature and pressure.
• the data and results given in table 1 prove that the selec­tivity of the conversion H2O2 ⁇ oxime is very ad­versely affected when operating under vacuum.
• Example 1 was repeated, bringing the pressure (gauge) to zero and considerably lowering the temperature (down to 15°C).
• the unsatisfactory results shown in table 1 prove that it is disadvantageous to excessively reduce the thermal level of the ammoximation.
• Example 1 was repeated, replacing titanium silicalite by a zirconite (zirconium-silicalite). Analogous results were obtained.
• Example 1 was repeated, replacing titanium-silicalite by a boralite (boron-silicate). Analogous results were obtained.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Catalysts (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

Country Status (8)

Cited By (19)

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• 1985
  • 1985-07-10 IT IT8521511A patent/IT1214622B/it active
• 1986
  • 1986-07-07 US US06/882,718 patent/US4745221A/en not_active Expired - Lifetime
  • 1986-07-09 AT AT86109400T patent/ATE60051T1/de not_active IP Right Cessation
  • 1986-07-09 ES ES8600203A patent/ES2000650A6/es not_active Expired
  • 1986-07-09 CA CA000513411A patent/CA1263408A/en not_active Expired
  • 1986-07-09 EP EP86109400A patent/EP0208311B1/en not_active Expired - Lifetime
  • 1986-07-09 DE DE8686109400T patent/DE3676893D1/de not_active Expired - Lifetime
  • 1986-07-09 JP JP61159898A patent/JPH0816091B2/ja not_active Expired - Lifetime

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